氟化钠的体外遗传毒性

In vitro Genotoxicity of Sodium Fluoride

[目的]研究氟化钠对小鼠淋巴瘤细胞(L5178Y TK+/-3.7.2c)微核的影响及其对中国仓鼠肺成纤维细胞(CHL)细胞染色体畸变及细胞凋亡的影响。[方法]以灭菌注射用水为阴性对照,采用胞质分裂阻滞微核细胞组学试验法,并以丝裂霉素(0.1μg/m L)为阳性对照,研究氟化钠3个浓度组(100、75与50μg/m L)对L5178Y TK+/-3.7.2c细胞总微核率、核分裂指数、核质桥发生率、核芽突发生率与含核突芽的双核细胞数/含Ⅰ型微核与含Ⅱ型微核的双核细胞数值的影响。以空白细胞为阴性对照,丝裂霉素(0.2μg/m L)为阳性对照,氟化钠以600、360、216和130μg/m L的浓度作用于CHL细胞,以观察其对CHL细胞致突变的作用。用流式细胞仪Annexin V/PI双染法检测氟化钠对CHL细胞凋亡的影响。[结果]与阴性对照组的相比:1阳性对照组(丝裂霉素,0.1μg/m L)和75、100μg/m L氟化钠组L5178Y TK+/-3.7.2c细胞微核率明显升高(P<0.05),且氟化钠三个浓度的氟化钠染毒组细胞核质桥发生率、含核突芽的双核细胞数/含Ⅰ型微核与含Ⅱ型微核的双核细胞数值均升高(P<0.01);2阳性对照组(丝裂霉素,0.2μg/m L)CHL细胞畸变率明显升高(P<0.05);氟化钠各染毒组畸变率差异无统计学意义(P>0.05),其早期凋亡率随染毒浓度的增加而上升(r=0.814,P<0.05)。[结论]氟化钠对L5178Y TK+/-3.7.2c细胞染色体具有损伤作用,对CHL细胞没有致突变作用,可以诱导CHL细胞的早期凋亡,呈现剂量相关性。

[ Objective ] To assess the effects of sodium fluoride （NaF） on mouse lymphoma cells （L5178Y TK＋/-3.7.2c） micronucleus and on chromosome aberration and apoptosis of China hamster lung fibroblast ceils （CHL）. [ Methods ] L5178Y TK＋/-372c ceils were treated with sterile water for injection （negative control）, mitomycin （0.1 μg/mL） （positive control）, and NaF （100, 75, and 50 μg/mL） to evaluate frequency of micronuclei, nuclei division index, nucleoplasmic bridges rate, nuclei buds rate, and nucleoplasmic bridges/micronuclei ratio. CHL cells were treated with blank （negative control）, mitomycin （0.2 μg/mL） （positive control）, and NaF （130, 216, 360, and 600 μg/mL） to evaluate selected mutagenic effects. AnnexinV/PI double staining method was applied for detecting cell apoptosis induced by NaF. [ Results ] Compared with the negative control group： （1） For L5178Y TK＋/-372c cells, the positive control group treated with 0.1 μg/mL mitomycin and the NaF groups treated with 75 μg/mL and 100 μg/mL had higher frequencies of micronuclei （P〈O.05）, and the three NaF groups showed elevated nucleoplasmic bridge rates and nueleoplasmic bridge/micronuclei （P〈 0.01）; （2） For CHL ceils, the positive control group treated with 0.2 μg/mL mitomycin had statistical differences in chromosome aberration （P 〈 0.05）; no significant difference of chromosome aberration was observed, in the CHL cells exposed to various NaF concentrations （P〉 0.05）, and the early apoptosis rate rose with elevated concentrations of NaF （r=0.814, P〈0.05）. [ Conclusion ] NaF could damage L5178Y TK＋/-372c cell chromosome. NaF shows no mutagenic effect on CHL ceils, but could induce CHL cell apoptosis in a dose-dependent manner.